You have one tree that produces big yellow apples and another tree that produces small red apples. when the two are crossed, you find that half the offspring trees produce big red apples and half produce big yellow apples. what are the genotypes of the parents? a = big apples; a = small apples; r = red apples; r = yellow apples. aarr and aarr aarr and aarr aarr and aarr aarr and aarr

The genotypes of the parents are AArr and aaRr

Since, half the offspring trees produce big red apples and half produce big yellow apples we can conclude:

That all of the offspring inherited dominant trait for the size of apple (all of them are big) so, AA from one parent and aa from another can combine and form all heterozygous genotypes Aa. On the other hand, trait for the apple color is expressed 50-50-% (rr and Rr form Rr Rr rr rr genotypes).

organisms that lack symmetry are called asymmetrical and belong to phylum porifera/sponges.

organisms with specialized stinging cells belong to phylum cnidaria. stinging cells are called cnidoblast cells.

cnidarians show two morphological forms : polyp (sessile) and medusa (mobile)

filter feeding is observed in porifera members.  

alternation of generation is observed in coelenterata or cnidaria. there is alternation of asexual polyp form and sexual medusoid form. it is also referred as metagenesis.

answer; i believe that the correct answer is ; males are hemizygous for the x chromosome;